Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 462,360	$ 519,446
Available for sale securities	0	50,875
Accrued interest receivable	0	348
Accounts receivable, net of allowances of approximately $29.1 million and $17.7 million at September 30, 2013 and December 31, 2012, respectively	103,757	85,893
Inventory	91,499	76,355
Deferred tax assets	13,889	13,881
Prepaid expenses and other current assets	12,165	9,577
Total current assets	683,670	756,375
Fixed assets, net	33,926	16,100
Intangible assets, net	622,274	119,576
Goodwill	186,821	14,671
Restricted cash	1,577	1,571
Deferred tax assets, net	0	46,625
Other assets	17,296	17,264
Total assets	1,545,564	972,182
Current liabilities:
Accounts payable	32,766	25,378
Accrued expenses	133,600	107,453
Deferred revenue	3,980	2,375
Total current liabilities	170,346	135,206
Contingent purchase price	188,554	18,971
Deferred tax liabilities	78,369	0
Convertible senior notes (due 2017)	233,544	226,109
Other liabilities	5,863	5,674
Total liabilities	676,676	385,960
Stockholders' equity:
Preferred stock, $1.00 par value per share, 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.001 par value per share, 125,000,000 shares authorized; 65,886,509 issued and 63,693,527 outstanding at September 30, 2013 and 56,153,140 issued and 53,960,158 outstanding at December 31, 2012, respectively	66	56
Additional paid-in capital	968,067	697,427
Treasury stock, at cost; 2,192,982 shares at September 30, 2013 and December 31, 2012, respectively	(50,000)	(50,000)
Accumulated deficit	(46,097)	(60,411)
Accumulated other comprehensive loss	(2,923)	(766)
Total The Medicines Company stockholders' equity	869,113	586,306
Non-controlling interest in joint venture	(225)	(84)
Total stockholders' equity	868,888	586,222
Total liabilities and stockholders' equity	$ 1,545,564	$ 972,182